Collector and insulator for electrical trolley apparatus



T. L. FORD ETAL Nov. 11, 1958 COLLECTOR AND INSULATOR FOR ELECTRICAL TROLLEY APPARATUS 4 5 w t 3 i 1 b e F m n 0 F 0 W m A M v m. a S E m m m TD A A E N&# .F E Y a M Jm r N?? r I Y fl fi fi JAMD I United tates atent COLLECTOR AND INSULAT'OR FOR ELECTRICAL TROLLEY APPARATUS Tirey L. Ford, Hillsborough, John B. Shaw, Redwood City, Alleyne C. Howell, Jan", San Francisco, Jacob Pfaif, Palo Alto, and David Rice, Newark, Calitl, as= signors to Insul-8-Corp., Burlingame, Califl, a corporation of California Application February 15, 1954, Serial No. 410,204

1 Claim. (Cl. 191--59.1}

This invention is a continuation-in-part of United States patent application Serial No. 307,062 for Electrical Trolley Apparatus, filed August 29, 1952, now U. S. Patent 2,704,309 granted March 15; 1955.

The main object of the invention is the provision of an improved collector head of the sliding shoe type.

Another object of the invention is the provision of an improved combination of collector head and conductor insulation which effectively reduces wear due to friction in the insulation and the collector.

Another object of the invention is the provision of a novel collector head which minimizes electrical leakage or short circuiting from the conductor to the collector.

Other objects and advantages will be apparent from the following specification and from the drawings.

Fig. 1 is a side elevational View partly broken away and in section of the collector head with a fragmentary portion of the insulated conductor engaged thereby.

Fig. 2 is a transverse cross-sectional view through the collector head as taken along lines 22 of Fig. 1.

Fig. 3 is an end elevational view of the collector head as taken along lines 33 of Fig. 1 and partly broken away and in section to show internal structure.

Fig. 4 is a side elevational view of the shoe support removed from the head.

Fig. 5 is a cross sectional view through a portion of the shoe support as taken along lines 5-5 of Fig. 4 and showing a shoe therein in elevation.

Fig. 6 is a side elevational view of a sliding shoe.

Fig. 7 is a top plan view of the leading portion only of the collector head as taken along lines 7--7 of Fig. 1.

Fig. 8 is a reduced end elevational view of a modified form of collector head and partly broken away and in section to show internal structure.

In detail, the collector head of Figs. l-7 comprises a pair of identical opposed cheeks or side walls 91, 92 which are mounted on the upper end of an upwardly extending trolley arm 106 (Fig. l). Trolley arm 106 comprises an elongated rigid tubular member 1117 of insulating material through which is passed a power lead 108 for conducting power from the trolley head 31 to the trolley base (not shown). The construction of the arm and base is such that the collector head is sprung upwardly against the conductor.

Secured to the upper end of member 197 is the closed end of a yoke, generally designated 109, having a pair of arms 11%, 111. The arms 111i, 111 are secured together at their outer ends by a bolt 112 with the head of said bolt in a socket 113 in arm 111! and with the end of the bolt shank threadedly secured in a threaded aperture 114 in arm 111. An insulating sleeve 115, surrounding the central portion of bolt 112 is interposed between the sides 91, 92 (Fig- To accommodate bolt 112 and sleeve 115, the sides 91, 92 are provided with apertures 117, 113 respectively for loosely receiving the opposite nds 0 SlfifiVfi 115 therein (Fig. 2). By this structure the collector ice head 31 is pivotally supported at the upper end of the trolley arm.

The opposedly directed sides of the arms 110, 111 are provided with oppositely inwardly opening slots 119, respectively within which are received the central portions of a pair of flat springs 121, 122 (Figs. 1, 2). Each of said springs extends generally downwardly and oppositely outwardly from said central portion and is curved so as to engage the lower sides of a pair of stops at its free ends. On side 91 of the collector head such stops comprise a pair of longitudinally spaced bosses 123, 124 and on side 92 similar bosses 125, 126. Another purpose for these bosses 123-126 will subsequently be described, but in connection with arms 110 and 111 of yoke 109 it will be apparent from Fig. 1 that springs 121, 122 cooperate wtih said bosses to urge the collector head 31 to the position of Fig. 1 and at the same time said springs yieldably resist pivotal movement of the collector head on the trolley arm. This structure permits the head to adapt itself to irregularities in the conductor track or irregularities in movement of the trolley base. To limit the movement of head 31 relative to trolley arm 111 6 a pair of longitudinally spaced stops 127, 128 are provided on each side 91, 92 (Fig. 1), which stops are adapted to be engaged by the free ends of the arms 110, 111.

Mounted between the sides 91, 92 is a shoe support, generally designated 130 (Fig. 4), for supporting a pair of longitudinally spaced shoes 29, 30 (Figs. 4, 6). The support 130 comprises a pair of opposed metallic plates 131, 132 (Fig. 5) each of which comprises a central longitudinally extending flat portion 133 and a pair of jaws 135, 136 integral with said central portion and at opposite ends thereof (Fig. 4).

Plates 131, 132 are rigidly secured as by rivets 137 (Fig. 4) to the upper end of a metallic block 138 which is adapted to be fitted between complementarily formed portions of sides 91, 92 (Fig. 2). This block 138 is formed with an opening 139 extending longitudinally of head 31 and is provided with a vertically extending clamping screw 140 for clamping the end of power lead 1%?) to the upper side of opening 139. In this manner a direct electrical connection is achieved between the lead 108 and the jaws 135, 136 of plates 131, 132.

The jaws 135, 136 of plates 131, 132 are provided with inwardly projecting ridges 141 which extend the length of said jaws longitudinally of the head 31. Said ridges 141 are preferably formed by bending the jaws 135, 136 so as to provide oppositely outwardly opening channels 142 (Fig. 4). The ridges 141 are adapted to engage oppositely outwardly opening grooves 143 formed in shoes 29, 30 (Fig. 4).

The sides 91, 92 of trolley head 31 are provided with oppositely inwardly projecting ridges 145, 146 integral with said sides and coextensive with outwardly opening channels 142 of jaws 135, 136. It will be apparent that upon movement of sides 91, 92 toward each other the pairs of jaws 35, 36 will frictionally engage the brushes 29, 30 and hold them against shitting relative to head 31. Upon movement of sides 91, 92 away from each other the brushes 29, 30 will be released so that the same may be removed through the upper side of the head.

For the purpose of releasably holding brushes 29, 30 stationary in head 31 a-pair of bolts 147, 148 are provided extending between sides 91, 92. Bolt 147 extends between bosses 123, 125, and bolt 148 extends between bosses 124, 126 hereinbefore referred to. Said bosses are provided with sockets for receiving the heads and nuts of the bolts as best seen in Fig. 17 and an insulating sleeve 149 extends between the sides 91, 92 to insulate the bolts from the brushes and brush support.

Centrally of the lengths of jaws 135, 136 of brush support 139 the same are apertured as at 151, 152 respectively for receiving bolts 147, 148 and sleeves 149 therethrough (Figs. 1, 3, 4) and the lower sides of shoes 29, 30 are provided with downwardly opening recesses 153, 154 for the same purpose. From the above described structure, it will be apparent that shoes 29, 30 may be quickly replaced by merely loosening bolts 14.7, 148 and it is not necessary to remove any parts of the head to substitute new shoes when the old ones are worn. Shoes 29, 30 are each provided with a .tivcly narrow transversely extending slot 150 having a predetermined depth. When the shoes are worn to the extent that the slots 150 disappear this indicates to maintenance personnel that the old shoes should be replaced with new ones.

To permit connection of power lead to the trolley head without disassembling the sides 91, 9.2 an opening 156 (Fig. l, 2) is formed along the bottoms of said sides for receiving a screw driver or wrench therethrough. In this manner the clamping screw 1.49 may be loosened and tightened as desired.

The leading and trailing edges of sides 91, 92 of head 31 are flared oppositely outwardly as best seen in Fig. 7 to enable the head to cross over gaps in the sheathing such as are present at switches, crane bridge interlocks, etc. Spaced downwardly from the upper sides of side walls 91, 92 at the leading edge thereof are a pair of oppositely inwardly projecting bosses 157, 153, respectively, which extend almost into meeting relation at the longitudinal central plane of the head 31. Integral with boss 158 on side 92 is a pin 159 which is slidably received at its free end in a complementarily formed hole 169 in boss 157. Said pin and hole constitute positioning means for retaining the sides 91, 92 in proper opposedly facing relationship at all times. A space 161 is left between the bosses 157, 158 to permit relative movement between the sides 91, 92 as above described. The trailing edge of head 31 is similarly constructed, but a pin is integrally formed in the boss on side 91 and a complementary hole 162 is formed in boss 163 carried by side 92. In this manner the sides 91, 92 are identical and may be cast from the same mold which is desirable.

In this same connection, the sides 91, 92 are complementarily formed with opposedly opening grooves 164 (Fig. 1) to form a longitudinally extending passageway for receiving the power lead 198. At corresponding points along said passageway the grooves 164 are enlarged to provide a substantially annular slot 165 (Figs. 1, 3). Inasmuch as sides 91, 92 are identically formed it will be apparent that the end of the passageway opposite the end which receives power lead 163 will be open (Fig.

. 1). To prevent accidental engagement of the block 133 through said passageway an insulating disc 166 is provided in slot 165 at the open end of said passageway. Disc 166 is preferably of such a size that it will not bind on slot 165 even when the side Walls 91, 92 are clamped tightly together.

Referring again to Fig. 2 it will be noted that the sheath 6, which acts as an insulator for the conductor generally designated 1, is provided with a pair of sides 7, 8 which, in turn include a pair of opposed faces 17, 18 respectively at the open side of said sheath.

The width of the shoes 29, 31 is made considerably less than the space between the opposed faces 17, 18 of the sheath 6, so that appreciable amount of lateral movement of shoes 29, 30 is possible before either of the faces 17, 18 is engaged by said shoes.

However, the spacing between the sidewalls 91, 9.2 of the collector head 31 is establiished with reference to the insulating sheath 6 so as to permit only a smaller amount of lateral movement of collector head 31 than is permitted by the spacing between brushes 29, 39 and the opposed sides 17, 18 of sheath 6.

Inasmuch as the shoes 29, 30 are firmly though releasably secured to collector head 31 it will be seen by the above described structure that sidewise movement of the collector head 31 relative to the conductor 1 is never sufiicient to permit the shoes 29, 30 to engage the sheath 6 although the collector head 31 and the sheath 6 may slidably engage each other.

Inasmuch as the wear attending sliding friction between the plastic sidewalls 91, 92 of the collector head 31 and the plastic sheath 6 is relatively small it will be understood that the life of the installation is not appreciably reduced by permitting such sliding friction to occur.

On the other hand, the amount of wear resulting from any sliding engagement between the copper shoes 29, 30 and the hard plastic sheath 6 is considerable, both with respect to the shoes and the sheath. By the particular combination of collector head and conductor sheath above described a considerable extension in the life of a trolley installation is effected over the life of a similar installation in which sliding friction between the brushes and the sheath is permitted.

In Fig. 8 there is shown a modified form of collector head generally designated 70. Coacting with head is a yoke 71 having the same function as yoke 109 on collector head 31 (Fig. 1).

in the form of Fig. 8,- instead of pivotally supporting the collector head on a bolt such as bolt 112, a pair of oppositely outwardly projecting bosses 72 are provided on'the collector. These bosses are oscillatably mounted within complementarily formed apertures 73 in the arms 74, of yoke 71. In other respects the structure of the collector head and yoke is the same as described above.

The apparatus of Fig. 8 has the advantage of minimizing leakage from the shoes to the yoke, such leakage being aggravated by accumulation of dirt and dust on the collector.

It should also be noted that, in all forms of the invention, the point at which the collector head is pivotally supported on one trolley arm is closely adjacent the point of contact between the shoes and the conductor. By this structure the shoe is maintained in sliding contact at all times and there is no possibility of chattering between the shoes and the conductor.

It should be understood that the foregoing detailed description of the invention should not be taken as restrictive of the same as it is obvious that variations in design may be resorted to without departing from the spirit of the invention as set forth in the following claim.

We claim:

An electrical system for collecting electric energy, said system comprising an elongated fixed conductor bar having a sheath of inverted U-shaped cross-sectional shape surrounding the conductor bar but leaving exposed a side to be engaged by the collector shoe of a trolley head, said trolley head comprising a body formed of electrical insulating material which is U-shaped in crosssections transverse to its length and to the conductor bar when engaged by the trolley head in use and having substantially vertical side walls of such vertical dimensions that the upper edges thereof extend above the spaced lower edges of the sheath when the trolley head is in operative engagement with the conductor bar, a block mounted within said trolley head body, flat, parallel, metallic plates connected to the opposite sides of said block and extending upwardly therefrom in spaced relation to each other and in parallel relation to and between the side walls of the trolley head body, said metallic plates being formed with inwardly facing ridges defining outwardly facing grooves, inwardly facing ridges formed on the inner surfaces of the side walls of the trolley head body and received within the outwardly facing grooves of said metallic plates, a collector shoe having side walls having outwardly facing grooves therein within which the inwardly facing ridges of said metallic plates are received to thereby support the shoe on and between the metallic plates, said shoe having an upper surface adapted to engage the conductor bar when the trolley head is in operative engagement therewith, said shoe being of such vertical dimension that said upper surface thereof is below the upper edges of the side walls of said trolley head body, the spacing between each side wall of the trolley 5 head and the adjacent side wall of the sheath being less than the spacing between each side of the shoe and the adjacent side wall of the sheath whereby the shoe is pre vented from engaging the side walls of the sheath on lateral movement of the trolley head with respect to the con- 10 ductor.

1,089,799 Spelling Mar. 10, 1914 15 6 Grace May 16, 1922 Chandler Mar. 26,1929 Wilkins Mar. 20, 1934 Schaake Nov. 12, 1935 Schaake Mar. 28, 1939 Wehr Dec. 8, 1942 Feist May 7, 1946 Connell Feb. 2, 1954 FOREIGN PATENTS Great Britain Feb. 4, 1944 

